Carrier 48FC Series Controls, Start-Up, Operation And Troubleshooting page 28

Fault F011 – MBB REFERENCE VOLTAGE
This fault occurs when the MBB internal microprocessor's DC
reference voltages is out of range. When this occurs the control will
shut down the unit. This will automatically clear when the DC
reference voltage goes back in range. The cause of this fault is
usually a MBB failure or supply voltage out of range.
Alert A012 – MBB ZERO CROSSING
This fault occurs when the MBB supply voltage frequency is out of
range. When this occurs the control will issue an alert. This will
automatically clear when the supply voltage goes back in range.
The cause of this fault is usually a MBB failure or supply voltage
frequency to high or to low.
Fault F013 – MBB FUSE 2 OPEN
This fault occurs when the MBB's internal fuse number 2 exceeds
threshold temperature. When this occurs the control will shut down
the unit. This will automatically clear when the fuse temperature
gets back in range. The cause of this fault is usually a switch input
has a wiring error (short) or the switch pulled too much current.
Discrete input number 2, Fire Shutdown input, and the IGC fan
request are connected to fuse 2.
Fault F014 – MBB FUSE 3 OPEN
This fault occurs when the MBB's internal fuse number 3 exceeds
threshold temperature. When this occurs the control will shut down
the unit. This will automatically clear when the fuse temperature
gets back in range. The cause of this fault is usually a switch input
has a wiring error (short) or the switch pulled too much current.
Configurable discrete input numbers 12, 13, and 14 are connected
to fuse 3.
Alert A015 – MBB RNET VOLTAGE RANGE
This fault occurs when the MBB's Rnet 12 volt output is out of
range. When this occurs the control will issue an alert, and any
accessory connected to the Rnet plug may not operate properly.
This will automatically clear when the voltage goes back in range.
The cause of this fault is usually a MBB failure or supply voltage
out of range.
Alert A016 – MBB 24VDC RANGE
This fault occurs when the MBB's 24vdc output falls below 17
volts DC. When this occurs the control will put the Analog Input
number's 6, 7, and 8 into error state. This will automatically clear
when the voltage rises above 19 volts DC. The cause of this fault is
usually a MBB failure or supply voltage out of range.
Alert A017 – MBB 5VDC RANGE
This fault occurs when the MBB's 5vdc output falls below 4.5
volts DC. When this occurs the control will put the Transducer
inputs into error state. This will automatically clear when the
voltage rises above 4.5 volts DC. The cause of this fault is usually
a MBB failure or supply voltage out of range.
Fault F018 – MBB EEPROM FAILURE
The unit will completely shut down. The serial EEPROM chip on
the MBB which stores the unit's configuration is not responding.
Recovery is automatic but MBB board replacement may be
necessary. Cycling the power to the control should be tried before
board replacement.
Alert A019 – MBB CLOCK FAILURE
The alert occurs when the RTC clock chip on the MBB is not
responding. Time and date functions will not operate, such as local
occupancy schedules. The unit will default to 24/7 unoccupied
mode. Recovery is automatic but MBB board replacement may be
necessary. Cycling power to the control and reconfiguring the time
and date should be tried before board replacement.
Fault F020 – SOFTWARE ERROR
The unit will completely shut down. The software on the MBB is
not responding. Recovery is automatic if the software is able to
reset the board but software change may be necessary. Cycling the
power to the control should be tried before board replacement.
Alert A100 – SAT SENSOR FAILURE
This alert occurs when the fan supply temperature sensor is in an
error state. Economizer cooling cannot occur while this alert is
active. The unit will not be able to honor SAT limits. This alert
resets automatically. The cause of the alert is usually a faulty
thermistor, a shorted or open thermistor caused by a wiring error,
or a loose connection.
Alert A101 – FST SENSOR RANGE
This alert occurs when the fan supply temperature sensor is outside
the range –40_F to 245_F (–40_C to 116_C). This alert resets
automatically. The cause of the alert is usually a faulty thermistor, a
shorted or open thermistor caused by a wiring error, or a loose
connection.
Alert A102 – FST OPEN SENSOR
This alert occurs when the fan supply temperature sensor reads as
an open circuit. This alert resets automatically. The cause of the
alert is usually a faulty thermistor or an open thermistor caused by
a wiring error, or a loose connection.
Alert A103 – FST SHORTED SENSOR
This alert occurs when the fan supply temperature sensor reads as a
short circuit. This alert resets automatically. The cause of the alert is
usually a faulty thermistor or a shorted thermistor caused by a
wiring error, or a loose connection.
Alert A104 – OAT SENSOR RANGE
This alert occurs when the outdoor air temperature is outside the
range –40_F to 245_F (–40_C to 116_C). All ambient temperature
lockout limits for cooling and heating are ignored. All cooling
control logic will assume OAT is high. For economizer equipped
units, the economizer will not operate to provide cooling. The
economizer will still operate for ventilation. The control will use
normal operation for outdoor fan control. For units with CCH
crankcase heat relay control, the crankcase heat relay will be turned
on if any compressor is off. This alert resets automatically. The
cause of the alert is usually a faulty thermistor, a shorted or open
thermistor caused by a wiring error, or a loose connection.
Alert A105 – OAT OPEN SENSOR
See Alert A104
Alert A106 – OAT SHORTED SENSOR
See Alert A104
Alert A107 - - RAT SENSOR RANGE
This alert occurs when the return air temperature is outside the
range –40_F to 245_F (–40_C to 116_C). Differential dry bulb
crossover control can not occur. Free cooling can only be
controlled by the OAT and enthalpy switch. The economizer
mechanically disconnected alert will not be diagnosed. This alert
resets automatically. The cause of the alert is usually a faulty
thermistor, a shorted or open thermistor caused by a wiring error,
or a loose connection.
Alert A108 – RAT OPEN SENSOR
See Alert A107
Alert A109 – RAT SHORTED SENSOR
See Alert A107
Alert A110 – SPT SENSOR RANGE
This alert occurs when the temperature is outside the range –40_F
to 245_F (–40_C to 116_C). Cooling and heating will not operate.
For economizer equipped units, the economizer will still operate
for ventilation. This alert resets automatically. The cause of the
alert is usually a faulty thermistor in the T- -55, T- -56, or T- -58
device, a shorted or open thermistor caused by a wiring error, or a
loose connection.
Alert A111 – SPT OPEN SENSOR
See Alert A110
Alert A112 – SPT SHORTED SENSOR
See Alert A110
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